New app for Android and iPhone called Facebook Messenger lets you quickly chat with friends

Facebook on Wednesday launched a brand new mobile app, for both Android and iPhone, called Facebook Messenger. And, if you and your friends are part of the social network’s 750 million members, this app could quickly become your go-to destination for messaging on the move.

The screenshot to the left is what you’ll see once you log into the app (though it will probably show your friends instead of mine). It’s basically a mobile-ified version of your social inbox on Facebook, which combines regular messages with chat messages so that all your communication with a single person flows in a long, unbroken stream.

As on the Web version of Facebook, you can also create and continue conversations with a bunch of people at once, which means group messaging on mobile actually be ready for the masses. GroupMe and other group messaging startups should look out.

Within conversations, you can share photos and your location with just a couple taps.

At its core, Facebook Messenger is a tweaked version of Beluga, the group messaging app that Facebook acquired in March.

“More and more of us rely on our phones to send and receive messages,” writes Lucy Zhang, Beluga co-founder and current Facebook engineer. “But it isn't always easy to know the best way to reach someone on their phone. Should you send an email or text? Which will they check first? Did they even get your last message?

“We think messaging should be easier than that. You should be able to write a message, click ‘Send’ and know that you will reach the person right away.”

SMS messaging isn’t the only messaging service that should feel threatened by Facebook’s new app. The iPhone’s next operating system, iOS 5, comes pre-packaged with iMessages, Apple’s attempt at unifying communication between iOS 5 users. And, of course, there’s Google, whose Google+ app has been trying to entice users with its Huddle feature, which is essentially group chat.